High-performance wireless (e.g., Wi-Fi, WiMAX, etc.) router and/or networking applications, such as, for example, multiple-input multiple-output (MIMO) 4×4 systems, generally employ a front-end module (FEM) which comprises one or more power amplifiers (PAs) and one or more low noise amplifiers (LNAs). The PA is employed to transmit radio frequency (RF) signals to an antenna, and the LNA is employed to receive RF signals from the antenna; an RF switch is utilized to selectively couple the antenna to either the PA or the LNA.
In many cases, there will be an insertion loss (typically in a range of about 0.2 decibels (dB) to 2.5 dB, or higher) attributable to the RF switch, which is undesirable; this insertion loss generally increases with increasing power and/or frequency. Although there are some known solutions for reducing switch insertion loss in the RF front-end module using complementary metal-oxide-semiconductor (CMOS) technology, such solutions are limited to low-power applications due to poor efficiency. For high-performance front-end modules, the technology used to fabricate the PA is based on a gallium arsenide (GaAs) substrate, while the technology used to fabricate the LNA is based on a CMOS silicon substrate, and the RF switch is typically fabricated on a silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) substrate or as a micro-electromechanical systems (MEMS) device. The different materials and technologies, however, make it particularly challenging to integrate the various front-end components on the same substrate.